Visibility of system
status
The system should always keep users informed about
what is
going on, through appropriate feedback within
reasonable time.
Match between sys
-
tem and the real world
The system should speak the users’ language, with
words,
phrases, and concepts familiar to the user,
rather than system-oriented terms. Follow real-world
conventions, making information appear in a natural
and logical order.
User control and
freedom
Users often choose system functions by mistake and
will need a clearly marked “emergency exit” to leave
the unwanted state without having to go through an
extended dialog. Supports undo and redo.
Consistency and
standards
Users should not have to wonder whether different
words,
situations, or actions mean the same thing.
Follow platform
conventions.
Error prevention
Even better than a good error message is a careful
design that prevents a problem from occurring in the
first place.
Recognition rather
than recall
Make objects, actions, and options visible. The user
should not have to remember information from one
part of the dialog to
another. Instructions or use of the
system should be visible or
easily retrievable when
-
ever appropriate.
Flexibility and
efficiency of use
Accelerators – unseen by the novice user – may often
speed up the interaction for the expert user such that
the system can cater to both the inexperienced and
experienced users. Allow the users to tailor frequent
actions.
Aesthetic and mini
-
malist design
Dialogues should not contain information that is irrel
-
evant or rarely needed. Every extra unit of informa
-
tion in a dialogue competes with the relevant units of
information and diminishes their relative
visibility.
Help users recognize,
diagnose, and recover
from errors
Error messages should be expressed in plain lan
-
guage (no codes), precisely indicating the problem,
and constructively suggesting a solution.
Help and
documentation
Even though it is better if the system can be used
without
documentation, it may be necessary to pro
-
vide help and
documentation. Any such information
should be easy to search,
focus on the user’s task, list
concrete steps to be carried out, and
not be too large.